A 1567 celestial globe showing the main Ptolemaic constellations attributed to Giovanni Vanosino is displayed at the exhibit "Astrum 2009: Astronomy and Instruments" at the Vatican Museum, in Vatican City, Tuesday Oct. 13, 2009. Rudimentary telescopes, celestial globes and original manuscripts from many astronomical scientists including Galileo are going on view at the Vatican Museums as part of an exhibit marking the U.N. International Year of Astronomy. The exhibit illustrates the history of astronomy, from a 3rd century A.D. globe of the Zodiac through the increasingly complicated telescopes used to gaze at the stars. (AP Photo/Pier Paolo Cito)

VATICAN CITY (AP).- Rudimentary telescopes, celestial globes and original manuscripts by Galileo are going on view at the Vatican Museums as part of an exhibit marking the 400th anniversary of the astronomer's first celestial observations.

"Astrum 2009: Astronomy and Instruments" traces the history of astronomy through its tools, from a 3rd century A.D. globe of the zodiac to the increasingly complicated telescopes used in more recent times to gaze at the stars.

At a briefing to launch the exhibit Tuesday, Monsignor Gianfranco Ravasi, the Vatican's top culture official, declined to revisit the Church's 17th century condemnation of Galileo for his discovery that the Earth revolved around the sun.

Church teaching at the time placed the Earth at the center of the universe.

Rather, Ravasi said that, while it was necessary to have the courage to admit errors when they were made, "I continue to believe that it's necessary to look more to the future."

The church denounced Galileo's theory as dangerous to the faith. Tried as a heretic in 1633 and forced to recant, he was sentenced to life imprisonment, later changed to house arrest.

The ruling helped fuel accusations that the church was hostile to science  a reputation the Vatican has been trying to shed ever since.

In 1992, Pope John Paul II declared that the ruling against Galileo was an error resulting from "tragic mutual incomprehension."

The exhibit, and other Vatican initiatives to mark the 400th anniversary of Galileo's telescope and the U.N.-designated International Year of Astronomy, is part of the Vatican's continuing rehabilitation effort.

One of the highlights of the show is Galileo's original manuscript of "Sidereus Nuncius," the 1610 document in which he excitedly recorded his first discoveries after using his telescope.

Tommaso Maccacaro, president of Italy's national institute of astrophysics, said it was important to look at the instruments not just from a scientific view but from a cultural one as well, since astronomy has had such an impact on the way we perceive ourselves.

"It was astronomical observations that let us understand that Earth (and man) don't have a privileged position or role in the universe," he said in his prepared comments to the briefing. "I ask myself what tools will we use in the next 400 years, and I ask what revolutions of understanding they'll bring about, like resolving the mystery of our apparent cosmic solitude."